Gear grinding machine



:I- 34,194. I. J. GRUENBERG ETAL 2,455,

GEAR GRINDING MACHINE Fild Jan. 21, 1946. v 2 Sheets-Sheet 1 li h m ||1| I'll n" n. g uu u u m n l ATTORNEYS ec. 14, 1948. R ENBERG ;T AL 2,456,410

GEAR GRINDING MACHINE Filed Jan. 21. 1946 2 Sheets-Sheet 2 INVENTORS IVOR J.GRUENBERG I BY SAMUEL G.BRADY ATTORNEYS Patented Dec. 14, 1948 UNITED STATES PATENT OFFICE *a45a410f g I 1 I GEAR GRINDINQMACH INE Ivor J Gruenberg,- Pleasant=Ri'dge, and Samuci G. Brady, Royal"ak,' Mioh., assignorsto TheGear .iGrinding Machine Company, Hamtramck, Mich.,'a:corporation of Michigan Application January "21, 194e,-'s'eria1 "Nb. 64 2,494

The invention relates to gear grinding machines of that type in which a formed grinder Wheel traverses the interdental space to fashion the teeth on oppositesides thereof. More particularly, the invention relates to grinding machines of the 'type in-which provision is made for grinding, a slight relief on opposite ends of each tooth. 'Heretofore, this has been accomplished. by means for vertically moving-the grinder wheel with-respect to its supporting frame during each working stroke. "Thiscomplica'testthe construction for his necessary that the grinder wheel shouldtbe vertically adjusted-in the'setting of the same withreference'to the work and'alsoin feedingit'into the work.

It is the object of the instant invention to 'obtain a construction capableof grinding relief at the ends of theteeth but onejinwhich thegrinder wheel remains stationary with respect to .the

frameduring each working stroke. 'To this end,

the inventionconsists in the construction as hereinafter set forth.

In the drawings:

Fig. 1 is a side elevation of a grinding machine of our improved-construction;

Fig. 2 is a cross section on line 22 of Fig. 1;

Fig. 3 is an enlarged elevation of a portion of Fig. 1, showing the relation between the eccentric supporting means for the platen and thecamand crank arm for adjusting the same;

.Fig. 4 is a perspective view of a finished .tooth with greatly exaggerated relief portions;

Fig. 5 is an end elevationthereof Figs. 6 and '7, respectively,=are plan views of side elevation, and

Fig. Bis a plan view of aportion of Fig. 3.

The object of grinding the relief is to lessen the stress on an end portion of the tooth when under load so as to avoid breaking of the same. The dimension of relief is very small, being generally only a fraction of .001 of an inch but in order to illustrate the construction, the relief is greatly exaggerated as illustrated in Figs. 4 to 7, inclusive. However, our improved construction may be adjusted to vary the dimension of relief to any degree desired.

The grinding machine may be of ordinary construction comprising a supporting bed A, a reciprocatory table B mounted thereon, a work holder C, including work supporting centers D and D and an indexing mechanism E. The mounting for the grinder wheel F is not shown but it will be understood that it is of usual construction, including means for adjusting the same 2 Claims. (Cl. :-51--'-.94)

with respect to thework. There is also preferably a trimming mechanism G'for the grinder wheel which is mounted on the table l3, sufficiently removed from the grinder wheel to permit the working stroke without interference with said wheel.

.Relzef Mechanism Instead of mounting the work holder C directly .onthetable Kit is. supported on a platen H, which later is mounted onthe table B'through the medium. of a pair of transversely extending shafts I and I engaging bearings 'J and ET on the .xumier :side :of the platen and provided at opposite .ends with zeccentric j ournal portions I These journal portions are mounted in bearings K'andJTK' on .opposite sides of the table B'and the axes :of .:the bearings J, K and J, K are in parallelPsubstantiallyvertical planes. Secured to one :end .OfithBEShaft I is 'a horizontally extendingrerank arm 'Lhavingawoller crank pin L. -M is :a cam for engaging the roller crank pin L, said cam being mounted onv'a-holder M, longitudinally .adjustably mounted on a member M which is longitudinally adjustably secured to the bed A. A .screw M :forms iameans for minutely adjusting the holder :M' .on the member-M while the latter :may be adjusted to difierent positions onathe'bed A to :correspond .to different positions of-zthework onithe holder'C. .The'arrangement is such "that during the reciprocatory movement-ofthe table'B,-the cam M, engaging therollerfL',willzrock the shaftI about the axis offthe eccentric journals 1- and through theiconnecting platen will impart a similar rocking movement to :the shaft I. Together, they impart a parallelogram movement' to the platen which has a vertical, as well as a horizontal com ponent with the latter of greater magnitude than the former. The horizontal movement of the platen relative to the table and to the left as shown in Fig. 1 is limited by a stop 0 on the table, engaged by an adjustable screw 0' on the platen. There is also a horizontally movable I plunger P telescopically engaging a socket P on the table and under the resilient pressure of a spring P in said socket, which plunger engages a lug P on the platen and impels the latter toward the limit imposed by the stop 0'.

Operation With the construction as above described, the work, such as a gear wheel N mounted on an arbor N, is engaged with the centers D and D. The member M is positioned longitudinally of movement of the crank arm L, due to longitudinal movement of the roller crank pin L overthe I cam M will depress the platen. The amount of depression depends on the length of the crank arm L and the shape of the cam M'so that by properly fashioning said cam, any desired.

What we claim as our invention is:

1. In a gear grinding machine, a frame, a grinder wheel mounted thereon, a horizontal reciprocatory carriage, a work supporting platen above said carriage, a pair of parallel shafts between said platen and carriage each shaft having a central portion journaled in said platen and corresponding eccentric end portions journaled in said carriage the axes of said central and eccentric end portions being in parallel substantially 7 vertical planes, a crank arm on one of said shafts, a cam adjustably mounted on said frame in the path of said crank arm to rock the latter and thereby raise and lower said platen at predeamount of vertical movement of the work withrespect to the grinder wheel may be obtained.

As previously stated, the amount of such vertical" movement is usually very small, such for instance as a fraction of .001 of an inch but the vertical movement of the crankarm by the cam is much greater which also contributes to accuracy.

Assuming that the table B is moved toward the left from the position shown in Fig. 1, this will cause the formed grinder wheel F to traverse an interdental space on the gear but during this movement, the platen is first lowered, then held stationary and finally raised.

As illustrated in Fig. 7, a movement of the work from the point a to the point 11 will lower the platen and work to produce the incline c. In the further movement of the work from the point b to the point :1, the platen will remain at constant height above the table and in the still 'further movement from the point d to the point e, the platen and work will be raised to form. the opposite incline f. Corresponding inclines g will be formed on the side faces of the end portions of each gear tooth with the result thatwhen the gears are in usein intermeshing relation with the conjugate gears, the load on the end portions of each tooth is relieved. 1 i I z One advantage of the construction above described over other constructions designed to accomplish the same character of grinding of the gear teeth, is that change in the diameter of the grinder wheel due to wear and trimming will not require any adjustment of the relief mechanism. Also, the table may at any time be moved to bring the trimming mechanism G in operative relation to the grinder wheel as the vertical relation of each to the bed remains undisturbed.

The construction is also one which can be manufactured with a high degree of accuracy and will be correspondingly accurate in the performance of its work. 1

termined points in the travel of said carriage, cooperating stops respectively on said platen and carriagefor limiting the relative horizontal movement thereof in one direction, and resilient means for yieldably holding said stops in contact.

2. In a gear grinding machine, a frame, a grinder wheel mounted thereon, a horizontal reciprocatory carriage, a work supporting platen above said carriage, a pair of parallel shafts between said platen and carriage each shaft having a central portion journaled in said platen and corresponding eccentric end portions journaled in said carriage the axes of said central and eccentric end portions being in parallel substantially vertical planes, a crank arm on one of said shafts, a cam adjustably mounted on said frame in the path of said crank arm to rock the latter and thereby raise and lower said platen at predetermined points in the travel of said carriage, cooperating stops respectively on said platen and carriage for limiting the relative horizontal movement thereof in one direction one of said stops being an adjustable screw, a spring pressed plunger and a lug the one on said carriage and the other on said platen adapted to yieldably hold said stops in contact.

. IVOR J GRUENBERG.

SAMUEL G. BRADY.

REFERENCES CITED Miller Mar. 7, 1944 Kaule May 29, 1945 FOREIGN PATENTS Country Date Germany June 6, 1930 Number Number 

